Muffler



Oct. 20, 1931.

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0 O O O 0 0 W Filed July 29, 1930 L. L. HAAS A AMKXW Patented Oct. 20,1931 'UNITED STATES PATENT- orrics LUcIEN L. mus, or BUFFALO, NEW YORK,nssrenon 'ro BUFFALO rnnssnn STEEL COMPANY, OF BUFFALO, NEW YORK MUFFLERApplication filed July 29, 1930. Serial No.-471,472.

" gases.

' Thelobjects of this invention are to provide a mufiler of this kindprovided with an improved arrangement of shells, resulting in two seriesof nested chambers into which the gases pass in succession, the chambersbeing tapered so that the gases enter into the portions of thechambersof greater cross sectional area and flow in these chamberstoward the portions of lesser cross sectional area' also toprovideamufller of thiskind,

in w job the two series of chambers are separated b a transversepartition having an improved arrangement of discharge openings for thegases; also to provide a mufiler go with a. series of relief openingswhich are arranged to prevent damage to the mufller in case of explosionof unburnt gases within the mufiier also to im rove the construction ofmufilers of this klnd in other respects as hereinafter specified.

In the accompanying drawings: Fig. 1-is a longitudinal, central sectionof a mufiler embodying this invention, on line 1--1 ,"Fig. 3;

Fig,1 2 is a fragmentary longitudinal secti'on t ereof, on line 2-2,Fig. 3; and Fig. 3: is a transverseisectional viewthere of, on line3'-3, Fig. 1.

The mufller shown in the accompanying ig'edrawings illustrates oneembodiment of my invention, and includes an outer shell or tube A and aninner shell B, both of'which preferably extend throughout the length ofthe mufiler and are connected at their ends to 40 heads 'C andD in anyusual or suitable mantension d connecting with the tail or dis- Both ofthese charge pipe of the mufller. heads are provided with the usualshoulders or cylindrical surfaces to which the shells A' and B may be.secured. Preferably, the

so shells AiandB substantiallycylindrical.

Intermediate of the ends of the muflier is arranged an annular bafile ortransverse partition E having its outer portion secured to the innersurface of the shell A, and its inner edge secured to the outer surfaceof the shell B. The inner shell B is also provided with a baille F,which divides this shell into two chambers. I

Between the two shells A and B and between the head C and the baflle orpartition E, a tapering shell G is provided, the smaller end of whichengages a shoulder 5 of the head C and contacts with the end of theinner shell B. This end of the shell G and the adjacent end of the innershell B may be suitably secured or welded to the shoulder 5 of the headC. The larger end of the tapered shell G bears against a shoulder 6 ofthe partition E,'which shoulder is preferably of elliptical shape, sothat the two chambers at opposite sides of the tapered shell G will benot only tapering lengthwise of the mufller, but also of irregularcontour transversely thereof.

Between the intermediate partition E and the head I) at the dischargeend of the muffler, another tapering shellH is provided, the smaller endof which fits snugly about the inner shell B and ma be welded thereto,if desired. In the welding of this shell to the inner shell B, thebaffle F may simultaneously be welded in place in the inner shell, sothat onewelding operation secures both the bafile F and the smaller endof the shell H to the inner shell B.

The larger end of the shell H engages and l preferably is secured to anannular shoulder 7 formed on the head D. This tapered shell H divides aportion of the space between the inner and outer shells A and B andbetween the partition E and discharge head D into two chambers, thecross sectional areas of which decrease from one end of each chamber tothe other end.

The gases, entering into the mufller through the inlet extension C, passinto the interior of the shell B, and then through a series of dischargeopenings or holes 10 in this shell, these holes being located at adistance from the inlet end of the muffler. The shell G is provided witha series of discharge openings 11 which are located nearer to the inlethead C of the mullier than are the holes 10 in the inner shell, so thatthe gases discharged from the inner shell through the holes 10 enterinto the portion of greater cross sectional area of the chamber betweenthe shells B and G, and then pass in this chamber toward the portion oflesser cross section and out through the holes 11 into the outer chamberbetween the shells G and A.

The gases collecting in the last mentioned chamber pass toward theportion thereof of least cross sectional area, and are then dischargedthrough suitable apertures in the battle or partition E. The aperturesin this bafiie or partition may be of any desired arrangement, butsuperior mutiler efi'ects are produced by arranging the apertures sothat a portion of the gases are discharged lengthwise of the muflier andanother portion transversely thereof. For this purpose, the battle E isprovided with a radially extending web portion let adjacent to theshoulder 6 and having a series of apertures 15 therein, through whichthe gases pass in a direction lengthwise oi the muiiler, and the web 1 Lterminates in an annular cylindrical shoulder 16 having a series ofapertures 17 therein, see Figs. 1 and 2.

As a result of the arrangement of the apertures in the partition E, aportion of the gases is discharged radially toward the axis of themuffler, and another portion of the gases is discharged at right anglesto the direction of the first portion, resulting in an intersecting ofstreams of gases and man implng ng o'f the gases which improves thesilencing of the noises resulting from the succession of suddendischarges of these gases. The gases, upon being discharged through theapertures 15 and 17, enter the end of greatest cross sectional area ofthe chamber 19 between the outer shell A and the tapered shell H, andthen pass through a series of apertures 20 in the shell H at the portionof the chamber 19 of lesser cross sectional area. The gases thus enterthe larger end of a chamber Ql between the tapering shell H and theinner shell B, and then pass through a series of apertures 22 at thesmaller end of the chamber 21, thus passing into a chamber 23 within theinner shell B, in which they are free to pass out of the muilier throughthe tubular extension d of the discharge head D. a

As a result of the elliptical shape of one end of the intermediate shellG, some of the gases flowing in the two chambers between which thisshell is placed, in addition to flowing lengthwise of the mufiier, flowin directions about the axis thereof. This action is further broughtabout by providing the discharge holes 15 in the partition at oppositesides only of this partition.

The mufiler described is of simple and inexpensive construction, andprovides for a )lilrality of separate and distinct chain ers throughwhich the gases pass in succession. Those chambers which are of varyingcross sectional areas are so arranged that the gases are in each casedischarged into the portions of these chambers of greater crosssectional area, and leave these chambers at the portions thereof oflesser cross sectional area, thus producing the reverse of a megaphoneeffect, which has been found effective in assisting in the silencing ofnoises from the exhaust of engines. In addition to these silencingeiiects, the two series of discharge openings in the bailie E alsoresult in a further silencing of the noises.

In mufflers of this kind, it sometimes happens that unburnt gases passinto the mufller from the engine and become ignited in the niuiiier,causing explosions in the mutfier, which damage the same. In most casesof internal explosions in mufiiers of this type, the intermediate shellG collapses as a result ofthe explosion. I have found that by providinga series of relief holes or apertures 25 in the inner shell adjacent tothe receiving end of the muffler, damage to the muifler as a result ofexplosions in the mufiler is prevented. These apertures have the furtheradvantage that during the normal operation of themufiler, a smallpercentage of the burnt gases pass through these apertures, and thusmeet the gases discharged from the apertures 10 in the chamber betweenthe shells B and G, and this impinging of gases also has a silencingefi'ect upon the same.

I claim as my invention 1. A muliler including inner and outercylindrical shells, a transverse partition between said shellsintermediate of the' ends thereof, a tapering shell arranged betweensaid inner and outer shells at one side of said transverse partition,and a second tapering shell between said inner and outer shells at theother side of said transverse partition, each tapering shell dividingthe space between the inner and outer shells into a pair of chambers ofgreater cross sectional area at one end thereof'than at the other end,and apertures in said shells and partition for discharging gasessuccessively into portions of said chambers of greater cross sectionalarea and discharging gases from portions of said chambers of lessercross sectional area.

2. A mufiler including inner and outer shells, heads at opposite ends ofsaid mufiler connecting said shells, a transverse partition intermediateof said heads and connecting said shells, a bafile in said inner shellintermediate of the ends thereof and dividing the same into twochambers, a taperin shell arranged in said inner and outer shel s andbetween one head of said mufller and said intermediate artition, and asecond tapering shell arranged in the space between said other head andsaid intermediate shell, said tapering shells forming chambers ofvarying cross sectional areas, and apertures in said inner and taperingshells and said partition for discharging gases into those portions ofthe chambers ad acent to said tapering shells which are of greater crosssectional area, and discharging gases from said chambers at the portionsthereof of lesser cross sectional areas.

3. A mufiler including inner and outer shells, means extendingtransversely of the mufiler for dividing the same into two groups ofchambers, and tapering shells arranged between the inner and outershells, one of said tapering shells being arranged at one side of saiddividing means, and the other tapering shell at the other side thereof,said tapering shells forming with said inner and outer shells chambersof varying cross sectional area, and means for discharging gases intosaid chambers of varying cross sections at the portions thereof ofgreater cross sectional area and discharging the gases from saidchambers at the port-ions thereof of lesser cross sectional area.

LUCIEN L. HAAS.

